Capsule and method of forming the same



W. WILKIE CAPSULE AND METHOD OF FORMING THE SAME Filed Nov. 19. 1923 avwzmtoz Patented Feb. 24, 1925.

UNITED STATES WARREN WILKIE,

or nn'raorr, MICHIGAN, or DETROIT, MICHIGAN, A 0

ASSIGNOR TO PARKE, DAVIS & COMPANY, ORPORATION OF MICHIGAN.

CAPSULE AND METHOD OF FORMING THE SAME.

Application filed November 19, 1923. Serial No. 675,7?9.

To all whom it may co /warn:

Be it known that I, WARREN Wmxm, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Gapsules and Methods of Forming the Same, of which the following is'a specification, reference being had therein to the accompanying drawings. 1

The invention relates to the manufacture of capsules or ampoules for containing a medicinal agent and it is the object of the invention to obtain a construction having chemical and physical properties which peculiarly adapt it for such use. One specific use of my improvement is for holding a solution of silver nitrate, but it is obvious that the construction is equally applicable to other uses.

In the present state of the art capsules or ampoules for holding solutions of silver nitrate have been formed of glass, beeswax and other materials. Where made of glass, the end must be fractured before the content is available and there is always danger of particles of glass being carried by the solution. Where made of beeswax, the end may be punctured and the content ejected by squeezing the capsule, but it has been found that there is a chemical reaction between the beeswax and the silver nitrate solution which destroys the purity of the latter. Other waxy substances, such as paraflin, are free from chemical reaction, but have not the physical characteristics for making a collapsible container. Thus if the walls are of sufficient thickness for strength, they will be too brittle to permit of flexing.

To avoid the objections to the various constructions as above described, I have devised a capsule or ampoule having flexible walls with a lining which is chemically inert to the content. For thecspecific purpose of holding silver nitrate solution, this capsule or ampoule is preferably of a composite form, including a thin walled lining of a chemically inert substance, parafiin or ceresin, and a surrounding heavy wall of a moreflexible and tougher material such as beeswax.

With this construction the silver nitrate comes in contact with the inner wall only and for a limited period of time it will remain entirely pure; However, upon aging of cellulose,

lating the beeswax from the liquid within the same.

- thin adherin such as I it has been found that even in these capsules decomposition of the silver nitrate takes place with the formation of free nitric acid and experimentation has revealed that this n is due to the permeation of the beeswax through the parafiin. To avoid this condition it is preferable to interpose between the outer wall andinner lining a coating of material resistant to the action of the beeswax. I have discovered that a number of materials may be employed for this purpose,

such as shellac, sandarac, copal or other In solution and collodion or other esters these materials eifectively isothe inner lining.

My preferred form of capsule, therefore, consists of an outer coating of beeswax to secure the proper degree 0 toughness and flexibility so that it may be squeezed or pierced without crumbling; an inner coating of some neutral mineral wax such as parafiin or ceresin to avoid chemical security for the contents of the capsule and a protective lining or coating between the two that will isolate the two waxes and prevent beeswax from permeating either the mineral wax or an air bubbles or other fissures in have also devised a process of manufacturing and filling such capsules as hereinafter more fully set forth.

In the drawings tion the various stages of manufacturing and filling the capsule or ampoule;

Figure 9 is a perspective view completed capsule. f

My improved composite.capsule or ampoule ma. be formed by dipping a tapering pin (Figure 1) into a solution of melted paraffin, ceresin or some other neutral mineral wax so as to form thereon a coating B, preferably about of an inc in thickness. then dipped into a vessel containing a protective material such as shellac, sandarac, co al or other gum solution or collodion or ot er esters of this operatlon forming a thin film C of protecting material around the inner coating The pm A 15 then dipped once again, this time in melted beeswax, to form a surrounding coatm greater thickness, preferably 0 an inch but leaving at the upper end a rojecting portion of the thin material orming of the The pin A is 7 the inner lining B. The composite structure may then be stripped from the pin and the capsule filled with the desired content E, such as silver nitrate, after which the projecting portion F of the inner linin is squeezed together as indicated at G to c ose the opening. This is sealed by fusing the ends of the adjacent upper end of the capsule is again dipped into the she'lac or other protective material and then into beeswax to complete the outer coating of the capsule.

he capsule or ampoule formed as described can be kept indefinitely without any injury to the content, inasmuch as the linmg or paraflin or ceresin has no deleterious effect upon the silver nitrate while the protective coating of shellac or other material prevents any penetration of the beeswax through the inner lining. The outer beeswax coating imparts the toughness and flexibility to the capsule so that whenever it is desired to eject the content the end may be perforated, after which the tion.

What I claim as my invention is 1. A compositecapsule .or ampoule coma thin inner wall of chemically wall being closed and sealed at its filling end and a surrounding coating of a tougherand flexible material.

capsule or ampoule comprising an inner wall of a material chemically inert to the content and of sufiicient thinness to be flexible, said inner wall being hermetically sealed at its filling end and a surroundin coating forming a thicker supporting wa of a material having greater flexibility and toughness. 3. A capsule or ampoule comprising aninner wall of a material chemically inert t o. the content and of sufiicient thinness to be flexible, being collapsed and sealed at its filling end, and a surrounding coating forming a wall of greater thickness and of a material havin greateeflexibilit and tou hness.

4. 5 capsule or ampou e ner wall of a material such rial of a more 111 orcing wall.

6. A composite capsule or ampoule comprising a thin inner wall ofa material chemically inert to the content, a surround ing coating of a tougher and flexible mawalls together, after walls may be collapsed to force out the solu-' an outer wall suflicient thinness to be flexible.

terial, and an intermediate lining of a material preventing the permeation of the latter into the, former.

A capsule or ampoule comprising an inner wall of a material chemically inert to the content and of sufficient thinness to be flexible, being collapsed and sealed at its ling end, a surrounding coating forming a wall of greater thickness and of a material having greater flexibility and toughness, and-an intermediate lining of a material for preventing the permeation of the outer material into the inner material to such an extent as to injuriously afl'ect the'content of the capsule.

8. A capsule or ampoule comprising a flexible inner wall of a material chemically inert to the content, such as paraflin, a surrounding coatlng of beeswax forming a thicker reinforcing wall, and an intermediate lining between said outer and inner walls for preventing the penetration of the beeswax into the inner material.

9. The method of forming capsules or ampoules comprising the dipping of a mold into a molten material to form a thin walled coating, and redipping the coated mold into a different molten material to form a thicker reinforcing coating.

10. The method of forming capsules or ampoules comprising the dipping of a mold into a molten material to form a thin Walled coating, redipping the coated mold into another molten material to form a surrounding reinforcing wall, leaving a portion of the thin'wall, filling the container, collapsing the projecting thin walls and sealing the same, and coating the projecting thin walled portion to complete the surrounding reinforcing wall.

11. The method of forming capsules or ampoules comprising the dipping of a mold in a molten material such as parafiin to form a thin coating thereon, redipping the coated moldinto a molten material such as beeswax to form a thicker reinforcing wall with a projecting portion of the thin wall, stripping the composite structure from the moldyfilling, collapsing the projecting thin walled portion and sealing the same, and coating said projecting portion with a bees- Wax to complete the reinforcing wall.

12. The method of forming capsules or ampoules comprising the dipping of a mold into a fluid material to. form a thin wall coating, redipping the coated mold into a different fluid film thereon, and again dipping the mold into a third fluid material to form a thicker reinforcing coating. L

-13. The method of forming capsules or ampoules comprising the dippin of a mold in a fluid material, such as para to form a thin coating thereon, redi ping the coated mold into afluid for protecting said coating,

projecting material to form a protective again dipping the coated mold into a third material, such as molten beeswax, to form tion of said capsule into the second mentioned material and finally coating said' projecting portion with beeswax to complete the reinforcing wall. 5

In testimony whereof I afiix my signature.

WARREN WILKIE. 

